(3-2) Imaginary Numbers

Solve the equation. (Pick 2)

 $x^2+9=0$  

•  $x=3$  

•  $x=-3$  

•  $x=3i$  

•  $x=-3i$  

Tags

CCSS.HSA-REI.B.4B

CCSS.HSN.CN.C.7

Solve the equation. (Pick 2)

 $x^2-9=0$  

•  $x=3$  

•  $x=-3$  

•  $x=3i$  

•  $x=-3i$  

Which of the following is NOT a solution to the following equation?

 $\left(x^2+121\right)\left(x+11\right)=0$  

•  $x=11$  

•  $x=-11$  

•  $x=-11i$  

•  $x=11i$  

Which of the following is a complex number?

• $\frac{22}{7}$

• $3.14$

• $\pi$

• $4+20i$

Click all the imaginary numbers. (Pick 3)

•  $3.14$  

•  $314i$  
  

•  $\sqrt{314}$  

•  $\sqrt{-314}$  

•  $-314\sqrt{314}i$  

What is the discriminant of the following equation?

 $x^2-6x+9=0$  

(a)  

You compute the discriminant and you get the number -77. What does this mean?

• The quadratic has two real roots.

• The quadratic has one real root.

• The quadratic has zero real roots.

Which of the following discriminants gives two possible real solutions to a quadratic?

•  $D=100$  

•  $D=-100$  

•  $D=0$  

What is the equation to determine the discriminant?

• $x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

• $b^2-4ac$

• $m=\frac{y_2-y_1}{x_2-x_1}$

• $y=mx+b$

• $A^2+B^2=C^2$

Simplify the square root:

 $\sqrt{-20}$  

•  $2\sqrt{5}$  

•  $-2\sqrt{5}$  

•  $2\sqrt{5}i$